import java.util.Arrays;

//最长数对链
//测试链接：https://leetcode.cn/problems/maximum-length-of-pair-chain/
public class FindLongestChain {
    public int findLongestChain(int[][] pairs) {
        // 预处理
        Arrays.sort(pairs, (a, b) -> a[0] - b[0]);
        int n = pairs.length;
        int[] dp = new int[n]; // 建表
        for (int i = 0; i < n; i++)
            dp[i] = 1; // 初始化
        int ret = 1;
        for (int i = 1; i < n; i++) {
            for (int j = 0; j < i; j++)
                if (pairs[j][1] < pairs[i][0])
                    dp[i] = Math.max(dp[j] + 1, dp[i]);
            ret = Math.max(ret, dp[i]);
        }
        return ret;
    }
}
